From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Paul Gortmaker <paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
Zefan Li <lizefan.x-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>,
Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Richard Purdie
<richard.purdie-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>
Subject: Re: [PATCH] cgroup1: fix leaked context root causing sporadic NULL deref in LTP
Date: Wed, 16 Jun 2021 11:23:34 -0400 [thread overview]
Message-ID: <YMoXdljfOFjoVO93@slm.duckdns.org> (raw)
In-Reply-To: <20210616125157.438837-1-paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
Hello,
On Wed, Jun 16, 2021 at 08:51:57AM -0400, Paul Gortmaker wrote:
> A fix would be to not leave the stale reference in fc->root as follows:
>
> --------------
> dput(fc->root);
> + fc->root = NULL;
> deactivate_locked_super(sb);
> --------------
>
> ...but then we are just open-coding a duplicate of fc_drop_locked() so we
> simply use that instead.
As this is unlikely to be a real-world problem both in probability and
circumstances, I'm applying this to cgroup/for-5.14 instead of
cgroup/for-5.13-fixes.
Thanks.
--
tejun
next prev parent reply other threads:[~2021-06-16 15:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-16 12:51 [PATCH] cgroup1: fix leaked context root causing sporadic NULL deref in LTP Paul Gortmaker
[not found] ` <20210616125157.438837-1-paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
2021-06-16 15:23 ` Tejun Heo [this message]
2021-06-30 16:10 ` Mark Brown
[not found] ` <20210630161036.GA43693-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2021-06-30 22:31 ` Richard Purdie
2021-07-01 12:11 ` Mark Brown
2021-07-01 12:43 ` Richard Purdie
2021-07-12 17:34 ` Tejun Heo
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